An RNA-based system to study hepatitis B virus replication and select drug-resistance mutations

Hepatitis B virus (HBV) chronically infects over 250 million people worldwide, increasing their risk of liver cirrhosis and hepatocellular carcinoma. There is a vaccine to prevent new infections, but no efficient cure for chronic infection. New insights into HBV biology are needed to improve cure rates for this widespread devastating disease. We describe a method to initiate replication of HBV, a DNA virus, using synthetic RNA. This approach has several advantages over existing systems: it eliminates contaminating background signal from input virus or plasmid DNA and can be easily adapted to multiple genotypes and mutants. Further, it can be applied to identify anti-HBV compounds, measure anti-HBV drug efficiency, study virus evolution, and, as we demonstrate, it can be uniquely applied to predict antiviral drug resistance.